Flapper type safety valve for subterranean wells
US4427071A · kind A · utility
34Cited by
3References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1982 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Feb 18, 2002 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/05
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The disclosure relates to an improved flapper type safety valve for use in subterranean wells wherein the flapper valve is actuated from a horizontal closed position to a vertical open position by contact from a downwardly moving actuating sleeve. The top surface of the valve is elevated so that the bottom edge of the actuating sleeve always contacts the flapper valve at a position maximally spaced from the axis of its pivot mounting, thereby assuring that the opening force applied to the flapper valve has a maximum moment arm in order to overcome any fluid pressure differential existing across the flapper valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.